Sometimes a character masturbates because the transformation process feels so sexually pleasurable to them. Other times, a character's desire to undergo a specific transformation, such as into a particular species or growing larger, is so intense that they need to pleasure themselves so they can trigger such a transformation. The character who is masturbating doesn't have to the be one transforming; there can be a character who masturbates because they want someone else to transform, and them masturbating somehow causes a different character to undergo a transformation.
If a character begins to masturbate after a transformation is complete, then it doesn't count for this tag.
Not to be confused with: